Test Bit Fields
TSTB
13-245
Assembly Language Instructions
Syntax
TSTB
src, dst
Operation
dst AND src
Operands
src general addressing modes (G):
0 0
register (R
n, 0
≤
n
≤
27)
0 1
direct
1 0
indirect (disp = 0–255, IR0, IR1)
1 1
immediate
dst register (Rn, 0
≤
n
≤
27)
Opcode
31
24 23
16
8 7
0
15
0 0 0 1 1
0
1
0
0
dst
G
src
Description
The bitwise-logical AND of the
dst and src operands is formed, but the result
is not loaded in any register. This allows for nondestructive compares. The
dst
and
src operands are assumed to be unsigned integers.
Cycles
1
Status Bits
These condition flags are modified for all destination registers (R27 – R0).
LUF
Unaffected
LV
Unaffected
UF
0
N
MSB of the output
Z
1 if a 0 output is generated; 0 otherwise
V
0
C
Unaffected
OVM
Operation is not affected by OVM bit value.
Mode Bit